Britain's transport infrastructure is ‘not fit for purpose’, with the cost of congestion likely to soon exceed the current figure of £20 billion a year, a report from a centre-right think tank said today.

Britain had the most crowded and congested roads, the fewest motorways and ‘some of the worst public transport’ among leading industrialised countries, the report from Policy Exchange said.

Congestion was now endemic, affecting not just large cities but also motorways and small towns, added the report which was produced in co-operation with task management company Serco and law firm Bevan Brittan LLP.

Congestion hotspots

For example, a six-hour peak time weekday charge of 10p per kilometre (10p/km) on a six-lane motorway priced to run close to capacity could in a year raise around £1.5 million per km - sufficient to pay for widening to eight lanes or, to construct a brand new six-lane motorway in parallel, the report said.

A charge of 5p/km for cars and light vans and 10p/km for goods vehicles on all roads could, in a year, raise over £25 billion - enough to pay for the construction of 1,200 miles of six-lane motorway.

In context, this would mean that a doubling in the size of the current motorway network could be paid for in under two years.

Transport infrastructure

A Department for Transport spokesman said: ‘The government is committed to tackling congestion and is making record investments in transport. This year we will spend around £900 million on improvements to major roads, including improvements to the M1 and M25.

‘However, we know we cannot simply build our way out of congestion. That is why we are working to get more from our existing roads through innovations like active traffic management, Highways Agency traffic officers and by providing better information to road users.

‘Road pricing - alongside public transport improvements - has the potential to cut predicted congestion growth by nearly half. That is why we are working with local authorities who want to develop local schemes and exploring pricing as a concept.’